Magnetic disk drives which write and read digital data from flexible magnetic disks have been extensively used. "Floppy disk drives" have been extensively used for small, so-called microcomputer systems, for word processing applications and the like. The flexible disk cartridge includes a relatively thin, flexible jacket which is inserted into the floppy disk drive.
"Bernoulli" disk drives having performance characteristics similar to that of fixed disk drives, but with removable cartridges, have been used. A flexible magnetic disk is enclosed in a rigid box which is normally completely closed. U.S. Pat. No. 4,400,748-Bauck, et al and related patents to the common assignee show such drives using Bernoulli stabilized flexible disks. U.S. Pat. No. 4,901,173-Jones et al and related patents to a common assignee, show improvements which relate to so-called "half height" drives.
Rigid disk drives, such as the IBM 3350, usually have a fixed rigid magnetic media. The magnetic heads do not contact the magnetic surface, but ride on a thin film of air. Because of this, and other features, these disk drives are capable of extremely precise and high speed operation. This type of disk drive is commonly referred to as a "Winchester" drive. Rigid disks enclosed in a rigid, removable cartridge, or shell have also been used. U.S. Pat. No. 4,864,452-Thompson, et al is an example of such a drive.
Winchester drives utilize a rigid magnetic media for recording the desired data. This is different from the flexible media found in Bernoulli drives. The JAZ.TM. drive sold by the assignee of the present invention uses such rigid media and Winchester type heads in data storage drives.
The particular shape of the cartridge visually identifies to the user that it can be inserted into the intended drive. However, this shape allows other similar sized cartridges to be inserted.
U.S. Pat. No. 5,768,074, Summer, et al. (Ser. No. 08/752,823) shows a cartridge for use with the JAZ.TM. Drive sold by Iomega Corp., assignee of the present applicant. The JAZ.TM. cartridge shown in this patent has keying slots which prevent improper insertion of the cartridge. Most removable cartridge drives (magnetic and optical) typically use approximately the same form factor cartridges, i.e., 3.5", 5.25", etc. Hence if one of these cartridges is inserted into the cartridge slot of a non-mating drive there is a high probability that either the drive (heads, load mechanism, electronics, etc.) or the data on the disk could be damaged.
U.S. Pat. Nos. 5,218,503 Martin and 5,280,403-Martin describe a disk drive with a cartridge which has a beveled edge. The beveled edge is compatible with a slanted portion of the disk drive in order to ensure that the cartridge is inserted into the drive in the proper orientation and that the cartridge is properly inserted in the drive, so that the heads can be unloaded onto the disk. U.S. Pat. No. 5,262,918-Tannert shows a cartridge having a door opening groove and a guide groove. The guide groove cooperates with an interlocking recess in the drive to center the position and hold the cartridge in the drive.
U.S. Pat. Nos. 5,398,141-Tannert and 5,422,775-Martin show hard disk cartridges and drives having 2.5"and 3.5"form factors respectively. These patents, assigned to SyQuest Technology, Inc., show cartridges having a square front. The SyJet cartridge sold by SyQuest.RTM. has a rounded front with "ears" on both sides.
U.S. Pat. No. 5,583,710-Nicklos, shows a disk drive having an automatic spindle motor loading mechanism that for the JAZ.TM.drive sold by Iomega, Corp., assignee of the present applicant. The JAZ.TM.drive shown in this patent as used for writing and reading data to and from a disk contained in a cartridge. The cartridge is inserted through an opening into the disk drive which includes a motor ring ratably mounted in the disk drive and a spindle motor for rotating the disk. The spindle motor is mounted in the motor ring such that rotation of the motor ring moves the spindle motor into and out of engagement with the hub of the disk cartridge. A position transducer provides an output signal indicating the essential position of the motor ring. A load/eject motor controls the rotation of the motor ring in response to the output signal from the position transducer.
A problem arises when the storage capacity of cartridges used in such drives is increased. With this increase, it is desirable that the new data storage drives will accommodate earlier disk cartridges. The new drive is capable of operating on prior cartridges having smaller data capacity. However, the converse is not true, the old data storage drives can not operate on the new data storage cartridges. This "backwards" compatibility is made possible by the present invention.